深厚含水基岩区立井外壁冻结压力的实测与分析

为明确我国西部深厚含水基岩区立井外壁的载荷，在鄂尔多斯市呼吉尔特矿区开展了基岩冻结压力的现场实测研究。结果表明：凿井期基岩冻结压力的变化规律可分为急剧增长、缓慢增长、快速增长、逐步减小4个阶段；基岩冻结压力主要受原岩富水条件、强度等因素的影响，与岩层埋深H关系不大；基岩冻结压力在混凝土浇注后的10~15 d即达到冻结压力最大值P max的76.4%~89.8%，建议采用7 d混凝土强度指标来保证外壁早期质量；基岩冻结压力在混凝土浇注后的80~100 d增长至最大值P max，P max实测值仅为1.08~1.74 MPa，远小于按岩层埋深H换算的静水压力值P 0，更远小于特厚冲积表土中的冻结压力上限值P ω。

In-situ measurement and analysis of freezing pressure of outer shaft lining in deep aqueous bed rock

In order to thoroughly investigate the load of outer shaft lining in deep aqueous bed rock area,in-situ measurements on freezing pressure of outer shaft lining were carried out in bed rock in Hujierte coalfield in Chinese Erdos.The in-situ measurement results reveal that the process of freezing pressure can be described by 4 periods:dramatic increase period,slow increase period,rapid increase period and gradual decrease period.The freezing pressure is mainly affected by rock moisture content and rock strength,but the rocks buried deep H affects little.The freezing pressure reaches 76.4%~89.8% of the maximum freezing pressure Pmax at 10~15 days after concrete pouring.Therefore,it is recommended using 7 days concrete strength index to guarantee the safety of outer shaft lining during the early period.The freezing pressure reaches the maximum value Pmax at 80~100 days after concrete pouring,the measured value of Pmax is 1.08~1.74 MPa.Pmax is much smaller than hydrostatic pressure P0 and the maximum freezing pressure Pω in deep alluvium.